The invention relates to a hydraulic bearing, or elastomeric support, which is provided with hydraulic damping through an arrangement of chambers that receive damping means, wherein at least two chambers are always interconnected by at least one channel. More particularly, the invention is directed to a hydraulic bearing with biaxial damping configured to dampen both axial as well as radial vibrations introduced in the mount.
Different designs of elastomeric bearings or rubber mounts are used for damping vibrations transmitted between connected parts of an assembly. (The terms “support”, “mount” and “bearing” will be used interchangeably in the context of the present specification and claims). Such bearings are used in large quantities particularly the automotive industry where they are employed, for example, as bearing bushings in the steering column linkage or as support for other chassis parts. Such bearing bushings are predominantly constructed to dampen radially introduced vibrations. Conversely, bearings with predominantly axial damping characteristics are employed, for example, as engine mounts for supporting the engine of the motor vehicle. Since it is desirable to further improve the driving comfort, in particular with respect to annoying vibrations and noise, simultaneous damping of radially introduced vibrations has become increasingly important in the engine mounts that were originally designed mainly for axial damping. Accordingly, biaxial bearings providing excellent damping characteristic for both axial and radial vibrations have been developed.
In particular, elastomeric bearings are frequently provided with hydraulic damping for damping vibrations with large amplitudes. To this end, at least two chambers receiving damping means are arranged in the body of the elastomeric bearing and interconnected by a channel formed in the bearing. In bush bearings, corresponding chambers are arranged in the radially outer regions of the bearing body and distributed along its circumference, whereas in axially damping bearings, the chambers are superpositioned in the axial direction.
However, hydraulic bearings with biaxial damping with a hydraulic component for both the axial damping direction and the radial damping direction are known in the art. Such hydraulic bearings with biaxial damping are disclosed, for example in DE 100 37 954 A1 and DE 103 34 901 A1. The bearings are constructed such that their elastomeric support spring simultaneously forms a part of an axially damping bearing as well as of a radially damping bearing. All the working chambers, namely the chambers for the axially damping bearing and the chambers for the radially damping bearing as well as the elastomeric support spring, form a one-piece component. However, this approach has the disadvantage that parameters which are important for the functionality in both damping directions (axial and radial) are directly dependent of one another and cannot be specified separately due to the one-piece design. In fact, any change in a desired axial damping characteristic of the elastomeric bearing body directly affects also its radial damping characteristic, and vice versa.